I have not been able to identify the supplier…
“…The bus is Alaska’s first and so far only electric-powered school bus. It’s in its second year of service for the school district. And with temperatures in the eastern Interior forecast to drop overnight to 20 below or colder in the coming week, it’s ability to operate in the cold will again be tested…”
Heating the buses in the evenings is an interesting issue. It suggests a bus depot with solar panels, some sort of energy or heat storage, and an air inlet and outlet port into the buses. That would work for legacy diesel buses as well.
For hot climates where the buses charge midday it is a little easier: solar panels for shade driving some sort of heat pumps that circulate air in the buses.